The embodiments herein relate generally to a self-contained prophy angle employing an effective delivery system for dispensing dentrifice in a controlled and economical manner.
A prophy angle is a generally small hand-held device used by dental clinicians to apply therapy to a patient, usually in the form of specially formulated prophy paste for teeth polishing. A rotating cup is often detachably affixed to the distal tip of the prophy angle at an angle to the main longitudinal housing of the prophy angle. The proximal end of the prophy angle is configured as a handle so that the dental clinician, such as a dental hygienist, can exert some comfortable force to polish a patient's teeth with prophy paste applied to the cup.
Traditionally, prophy paste is manually applied to the cup prior to its insertion in the mouth, and then the cup applied to the patient's teeth while power is applied to the device to rotate the cup at a fairly high speed. In that regard, the proximal end of the prophy angle comprises a housing with an opening for accepting therewithin, typically via friction fit, a handle containing a drive mechanism. Historically, the drive mechanism was powered by a tethered drive cable, but since then the drive mechanism comprises a pneumatically-driven motor powered by a tethered air hose. The drive motor is conventionally configured to engage a drive shaft extending from the proximal end of the prophy angle. The drive shaft is axially positioned generally centrally within the prophy angle such that, at a distal end of the drive shaft, a set of bevel gears is typically provided that, in turn, rotatably drive the cup positioned at about an angle normal to the drive shaft.
Over the years, numerous configurations of prophy angles have been presented, with many never becoming commercialized. A prophy angle is intended to be a sturdy but generally light-weight device that is intended for single use only in an effort to address certain infection control issues in the dental practice. Certain bells and whistles have been suggested for the prophy angle over time, but one that has value, but has not yet been commercialized, is a pre-charged prophy angle; i.e., a prophy angle containing a chamber for storing prophy paste and means for discharging the paste as needed. In that regard, numerous patents have been issued on the general scheme of a self-contained prophy angle, including U.S. Pat. No. 2,400,912 to Britt et al.; U.S. Pat. No. 3,389,468 to Lewis, U.S. Pat. No. 3,579,835 to Levenson, U.S. Pat. No. 3,769,707 to Condon, U.S. Pat. No. 3,775,849 to Condon, U.S. Pat. No. 3,987,550 to Danne et al., U.S. Pat. No. 4,220,446 to Walker, U.S. Pat. No. 4,266,933 to Warden et al., U.S. Pat. No. 5,062,796 to Rosenberg, U.S. Pat. No. 5,208,933 to Lustig et al., U.S. Pat. No. 5,642,994 to Chipian et al., U.S. Pat. No. 5,871,353 to Pierce et al., U.S. Pat. No. 5,927,976 to Wu, U.S. Pat. No. 6,632,090 to Randolph, U.S. Pat. No. 7,070,412 to Stadeker, U.S. Pat. No. 7,101,182 to Garrison et al., U.S. Pat. No. 7,160,108 to Jaffe, U.S. Patent No. Appl. No. 2009-0098505 to Randolph, and PCT Appl. No. W02009-140630 to Bellanti. None have been known to be successfully commercialized, ostensibly because they are generally not clinically relevant, not cost effective or commercially viable.
By way of specific example, FIG. 1 herein reflects figures from the '912 patent to Britt et al. The disclosed device includes a means of forcing the paste from a chamber to a recess in the tool, which includes a plunger mounted for reciprocation in the chamber that engages the shell and has formed therein a central opening to accommodate the shaft and the shell therearound. With the chamber filled with paste and the plunger in the retracted position, appropriate forward movement of the plunger forces the paste out through the tube and passages. The mechanism of action, as reflected by the arrangement of components in FIG. 1 herein, however, evidences a level of complexity that makes operation inefficient and terribly cost inefficient to manufacture.
By way of an additional example, FIG. 2 herein reflects a figure from the '468 patent to Lewis. There, a housing is disclosed that is pre-charged with a quantity of paste prior to the insertion of a piston within the housing. Rotation of the drive shaft in a direction for moving the piston toward the shoulder forces the paste within the chamber outwardly through the passageway and through the passageway into the interior chamber of the prophy cup. Simultaneously the rotation of the drive shaft rotates the gear that, in turn, transmits rotation to the cup. Among other limitations, the Lewis device suffers from a lack of control of paste discharge, as the action of discharge is controlled by the system driving rotation of the prophy cup. The other prior art prophy angles, even those containing a pre-charging feature, suffer from similar limitations.
As such, a need has arisen for an effective and cost efficient pre-charged prophy angle to meet the dental treatment needs.